There is value in a 1986-7 radiator, as it is unique the only these 2 years.
No other GM, or any make vehicle, ever used an end tank with pipe fittings for the tranny cooler lines.
I will gladly pay you for the cooler end tank and shipping, just cut off the old core about an 1" from the tank if you decide to do this.
In the 1990's I was selling 100 or so recored radiators a summer, and it was rebuilt with a special high efficiency core that provided cooling equal to or better than some alum replacements.
Copper transfers heat better than alum, but is also more expensive.